Showing events on this day in years past that shaped history... just, not our history.

Thursday, June 30, 2011

June 30, 1908 – Tunguska Impact Alters the World

In an event unable to be understood at the time, a pinpoint black hole struck the Earth near the Stony Tunguska River in Siberia, Russia. The impact itself was significant with a shockwave estimated at 5.0 on the Richter scale that knocked trees flat in an 800 square mile spread, blew people off their feet, and destroyed windows for hundreds of miles. The aftershock, however, was far more important. As the black hole bore through the Earth, it shed the event-horizon shell of cosmic matter and evaporated with the energy from friction and pressure of the Earth's core. The shockwaves continued through the molten core and mantle like an isolated earthquake, meeting on the opposite side of the world near the Strait of Magellan. There, the edge of the Antarctic Plate buckled with the South American Plate, causing a massive upheaval that would turn the Drake Passage into an enormous mountain range connecting the Andes and the Antarctic Peninsula.

Newspapers and scientists would consider the event purely tectonic until the Leonid Kulik expedition in 1921 determined the mysterious explosion happened only hours before the upheaval. His mineralogy team excavated radioactive material not uncommon to Siberia that would later be tested again in 2007 and found to coincide with isotopes from space such as cesium as well as heavy polonium and magnetic nickel.

At the time, however, the world's attention was turned to the new landmass that had suddenly cut off the Atlantic and Pacific Oceans (what would later be termed as the “exit wound” of the black hole, though it was really only backlash from the collision). As ocean currents adjusted, climatological alterations began such as the increase of rainforest to the south of the Amazon and the widening of the Kalahari Desert. Sea life suffered greatly as migration routes were cut off, causing the extinction of several whale species, already over-hunted. Most notable to the time was that the most-used passage to the Pacific had been cut off. Since its discovery by Balboa, the Pacific had struck Europe as a new, calmer ocean for exploration and colonization. The Pacific had been especially instrumental to the Americans, who used it as the main route connecting them to the quickly populated West Coast even after the construction of the Transcontinental Railroad. A faster route was currently under construction through a canal in Panama, but at the time of the Upheaval, it was still years from completion. The long-sought Northwest Passage had only recently been completed by Roald Amundsen from 1903 to 1906 and could be crossed only at the warmest points of summer by reinforced icebreaker ships.

Effectively, the Pacific had become cut off from the East. Shipping could still flow through the Indian Ocean, but the journey from New York to San Francisco by steamer had increased from weeks to months. Calling the times “desperate,” US President Theodore Roosevelt began his campaign for his unprecedented third term and vowed not to leave office until his canal was completed (which occurred years before schedule in 1911). The rest of the world looked with shock and envy at America controlling the only access to the eastern Pacific, and soon multiple European-backed companies began plans to dig canals through Honduras, Costa Rica, and, especially, Nicaragua. Only the Nicaraguan Canal would see completion in 1923, after changing hands twice.

Other plans, however, determined that overland routes would be suitable. On February 12, 1908, the New York to Paris Race began, traveling by motor car and partially by steamer west from Times Square to the French capital. A month after the Upheaval, the American team arrived victorious in their Thompson Flyer. Savvy newspapermen used the event as an example of the efficiency of overland travel. The Germans (whose team arrived second), took notice of the feat and began work with the ABC Powers (Argentina, Brazil, and Chile) to complete a rail and motorway that would bring goods from Buenos Aires to Santiago. German imperial attention turned to South America, bringing commerce and tourism, so much so that commentators doubted the Kaiser had even noticed the short-lived Austrian occupation of Serbia.

Gradually, the world would become accustomed to its new scar of what came to be known as the Drake Mountains, but the idea that an object from space could bring such devastation to a planet continues to unnerve the human spirit.

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In reality, the mysterious Tunguska blast was most likely an air burst of a meteoroid. It produced an explosion that would not be rivaled by man until atomic weapon tests of the 1950s. Other hypotheses about the explosion have labeled it the activity of antimatter, aliens, Nikola Tesla, or, famously in 1973, University of Texas physicists Albert Jackson and Michael Ryan suggesting the idea of a small black hole (though it would not have left the telltale minerals found in later expeditions).

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More info on Tunguska at Matt's Today in History blog. http://mattstodayinhistory.blogspot.com/2011/06/tunguska-event-june-30-1908.html

2 comments:

You really underestimate what all this would entail. You'd end up displacing fifty million cubic kilometers of water in making the Drake Mountains. The resulting Tsunamis would wipe South America, Africa, and Australia clean. The resulting release of energy as the black hole left the earth would boil water over three quarters of the globe and flash melt lunar regolith if the moon was in the right position.

To quote a friend who read this alternate, "It would be bad, really bad." This would be an extinction level event.

Drake Passage averages 3,400 metres deep and 1,000 km wide. Depending on how much area uplifted, anywhere from just an isthmus to an entire subcontinent, so from about 200km-3,000km, volume of water displaced ranges from 680,000 km3 to 10.2 million km3 with a world wide sea level rise of 2-9 feet.

Emergent islands themselves don't seem to cause tsunamis, probably because the actual rise is slow, but in this case the tectonic action would cause a tsunami to dwarf any that we know about. Taking 1960 Valdivia as an example, that was just off the coast of Chile but people in Japan died. I don't think Australia would suffer much because New Zealand would block the waves, but Atlantic coast South America and Africa could get a stiff dose. The remoteness of the epicenter from densely populated areas would greatly lessen damage and casualties, but it would still be bad.

He's saying that the black hole was small enough that it never exited the Earth. All its energy was released inside and that is what caused this extent of tectonic action.

The climatic impacts are what could be truly devastating. Probable melting of the Antarctic ice cap and definite disruption of the thermohaline circulation which would entirely disrupt world agriculture. We're looking at effects at least equivalent to the Year Without a Summer, and possibly much worse.